Steering column assemblies or steering columns of the type in question are used for fitting in a motor vehicle and transmitting the torques applied by the driver to a steering wheel into a steering system of the vehicle. Furthermore, steering columns have to stand a variety of loads during use, in particular when the vehicle collides with an obstacle—the crash case.
DE 10 2005 034 952 B3 discloses for example a steering column which is adjustable in its height and its inclination. A steering spindle is mounted rotatably in an adjusting part, which is also referred to as a casing unit. The casing unit is held in a retaining part and the retaining part is mounted in a retaining clip, which can be fastened to a vehicle body. Provided for adapting the position of the steering spindle, or a steering wheel fastened thereto, is a clamping system, which can be adjusted by an adjusting lever between an open position and a closed position. In the open position of the clamping system, the casing unit can be displaced in its longitudinal direction with respect to the retaining part and at the same time the retaining part can be pivoted in its inclination with respect to the retaining clip about a pivot axis. In the closed position of the clamping system, the steering spindle is fixed with respect to the retaining clip, which is fixed to the body. Such steering columns and clamping systems are known in various configurations in the prior art.
In keeping with the prior art, the components of such steering columns are made of cast steel, aluminum or magnesium.
To favorably influence fuel consumption and to improve the driving dynamics of motor vehicles, and also to increase the range of electric-powered vehicles, there is a general desire to make such steering columns particularly lightweight and of great rigidity. For this purpose, DE 101 55 891 B4 proposes generally making the casing unit that forms the central bearing tube from a thermoplastic or a thermoplastic tube with a glass-fiber or carbon-fiber filling. However, how such a bearing tube may actually be formed is left open by the disclosure.
EP 0091671 B1 discloses a safety steering column, in which a tube part of the steering spindle is formed in one piece with a rigid steering column portion of fiber-reinforced plastic. In this case it is disclosed that the steering column is produced by a technique of winding around a core, for example of rigid polyurethane foam. However, this greatly restricts the possibilities for the design of the steering column.
DE 102 42 527 A1 discloses a steering column supporting housing consisting of a polymer composite material and having a mounting support, the steering column supporting housing and the mounting support comprising a multiplicity of fibers within a composite material.
Furthermore, DE 198 09 264 A1 discloses a fibrous structure arrangement and a process for producing a preform. In the fibrous structure arrangement, individual layers of fiber are laid one on top of the other and sewn with sewing threads, in some cases with adhesive mats inserted as intermediate layers. This arrangement includes a meltable layer, which is only activated during a forming process and, after forming into a desired three-dimensional shape, provides permanent solidification of the preform.